Technologies of synchronous rectification (SR) use a low-voltage power metal-oxide-semiconductor field-effect transistor (MOSFET) as a rectifier. With its low forward voltage drop and small on-state resistance, the overall power consumption of the rectification module may be reduced. The main difficulty in using the technologies of synchronous rectification lies in gate control of its rectification MOSFET.
The rectification MOSFET is mainly driven in a pulse width modulation (PWM) mode, which is complicated to be implemented and needs to establish a space vector mathematical model to perform a complex transformation solution. A great number of logic processing is required in circuit construction, and thus technical difficulties and costs are increased. Application of an external power supply driving mode is relatively complicated, whereas an independent charge pump self-driving mode has a slow charging speed, which is disadvantageous to popularization and application of the technologies of synchronous rectification.